/*
 * Copyright (c) 2002-2012 Alibaba Group Holding Limited.
 * All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.alibaba.antx.config.generator.expr;

/**
 * 代表一个常量表达式，该表达式的值不依赖于context。
 *
 * @author Michael Zhou
 */
public class ConstantExpression implements Expression {
    private String value;

    public ConstantExpression(String value) {
        this.value = value;
    }

    public String getExpressionText() {
        return String.valueOf(value);
    }

    public Object evaluate(ExpressionContext context) {
        return value;
    }

    @Override
    public String toString() {
        return getExpressionText();
    }
}
